Ecuador’s remote oilfields and oil pipelines require a reliable source of low cost electricity. The use of crude oil and associated gas to generate power is an obvious solution, but using ‘fuel off the well’ can present a number of challenges.
Deep in the Ecuadorian Amazon jungles, far from the convenience of the national electricity grid and roads, the Dygoil oil service company has invested in a plant which will supply power to its oil wells and central processing facility, using heavy crude oil or associated gas as fuels.
The plant that will utilize this low-cost resource comprises two dual-fuel Wärtsilä 16V32GD engines running on crude oil and associated gas: fuels that are readily available at the site and virtually cost-free.
The Wärtsilä delivery is a turnkey power plant, which has an output of 11 MW. Electricity generated by the plant will be distributed by local electrical medium voltage grid to the oil wells and the central processing facility. The project is estimated to be fully operational in January 2004.
The Dygoil project in Secoya town is an example of a site that uses Wärtsilä’s engine technology to process challenging fuels. An Ecuadorian company, Dygoil is the main contractor of Petroproduccion – a subsidiary of PetroEcuador.
Figure 1. View of the Occidental Eden Yuturi oil field development site in Ecuador
Speaking about the benefits of using this technology, Lars Gustaf Martin, General Manager, Wärtsilä said: “These engines offer oil exploration companies that operate far from civilization and available power grids a low-cost and environmentally friendly solution to a major power supply problem.”
Wärtsilä has many other contracts for operations in the Ecuadorian region. This is because there are vast oil reserves in the Amazonian jungles. However, the main dilemma in this area is the best means of transporting the oil to the world market. To the east lies the jungle and to the west, the sky-high Andes mountains. Existing transportation systems reached full capacity more than ten years ago, and the main issue hampering oil production in Ecuador throughout the last decade has been the shortage of additional energy and oil transport capacity.
Today, Ecuador is the hub of Wärtsilä’s operations throughout northern and western South America. These activities have provided solutions to the common transport and power problems, which can hamper remote oil exploration projects, such as Dygoil.
Booming oil sector
The most important oil project in the country for the last 20 is the Oleoducto Crudo Pesado (OCP – Heavy Crude Pipeline), which is now coming into operation. This pipeline will enable Ecuador to double its exports of crude oil. Wärtsilä has been heavily involved in this project.
Wärtsilä was awarded the contract to supply 22 pumping units and six power generating sets for the four pumping stations needed along the pipeline. Each pump unit consists of one Wärtsilä 12V32LN crude oil fuelled driver engine, including auxiliary equipment, a speed increasing gearbox and a centrifugal pump. Wärtsilä also provided the power stations for two of the pump stations: Amazonas and Sardinas. The main generator sets are crude oil fuelled engines with a standby engine operating on light fuel oil.
This major project has opened up opportunities for companies in the region to make new plans to optimize their existing oil and production facilities, build more efficient ones and increase their transportation capabilities. Wärtsilä has now become the main supplier of power generation equipment and power plants for most of these oil companies. Its goal is to successfully fulfil all of its contracts, ensuring that Wärtsilä powers Ecuador’s new crude oil production capacity.
Figure 2. Ecuador’s OCP pipeline and Wärtsilä power stations
Associated gas is usually free of charge and is sometimes flared off by oil producers. However, companies such as Dygoil can burn all their associated gas in engines and top this up with crude oil, in case the gas is not enough to maintain supply.
Wärtsilä’s diesel and multifuel engines allow such companies to achieve this. Wärtsilä’s multifuel engines can be fuelled by various oil production hydrocarbons from the field process, such as heavy oils and different types of crude oil and associated gas.
These true baseload engines are designed for continuous duty in severe applications. The extensive engine programme covers unit outputs ranging from 600 kW (800 hp) up to 17.5 MW (23 800 hp). Uncompromising multifuel performance results from a competitive output/weight ratio, high efficiency and good tolerance to variations in fuel quality. And of course, absolute reliability with no costly downtime or interruptions in power generation during fuel changes.
Because of their location and testing environmental conditions, oil and gas field applications require a power generation system with outstanding reliability and a high degree of fuel flexibility. Outages come at a premium, and manpower is expensive. Fast-track delivery is also important, so when oil or gas has been found, production can begin immediately.
Flexible fuel engines
Over the years Wärtsilä has developed a number of fuel configurations to the base engine models. These engines are from the outset designed for demanding heavy fuel oil (HFO) operation, with viscocities up to 730 cSt/50ºC, density up to 1.013 kg/dm3, sulphur up to five per cent and high metal content.
The HFO operation requires high temperatures and high peak pressures to achieve complete combustion, thus the main parts of the engine, like engine block, crankshaft, connecting rod and piston/liners must be appropriately designed to withstand the high thermal and mechanical load.
The multitude of impurities in the HFO also places a stringent demand on the proper design of moving parts coming in contact with the fuel and combustion gases, as well as over-sizing of the lubrication system.
Based on the basic HFO design, the GD (Gas Diesel) concept was introduced in 1987. This concept allows virtually any type of petroleum-based fuel to be used. For example, heavy and sour crude oil, HFO, natural gas, associated gas, and diesel oil among others have been successfully used as fuel for these engines.
Figure 3. Oil and gas field applications require a reliable power generation system with a high degree of fuel flexibility
The latest development of the GD concept allows stepless variation of the amount of liquid and gaseous fuel. This is particularly interesting when the amount of gas is limited.
In the early 1990s the spark ignited gas engine (SG) concept was introduced. The Wärtsilä SG engine family incorporates spark ignited, lean burn, pre-chamber engines with port injection of the gas.
The exact control achieved with the port injection of the gas, the total electronic engine control system and the possibility to choose compression ratio depending on the gas quality, has made the Wärtsilä SG engines a versatile power generation option for varying gas qualities. More than 1000 engines have been put into operation based on this successful design.
The dual-fuel (DF) is a relatively recent technology concept that was introduced in mid-90s, with the first engines now passing 50 000 running hours. The DF engine can operate both on gas and liquid fuels and principally work according to the lean-burn principle in gas mode, whilst it operates according to the diesel principle in liquid fuel mode.
All these engines operate on high electrical efficiency of 42-48 per cent shaft efficiency (heat rate of 8500-7500 kJ/kWh) dependent on size and configuration. For the operator this means an outright saving in fuel costs of 20-40 per cent compared with traditional solutions comprising low efficiency gensets or gas turbines.
In addition, the operator gains a superior operational flexibility allowing him to use the fuel, which becomes the cheapest overall solution. Depending on which fuel comes at the lowest cost and in which combinations, the proper engine configuration can be chosen to minimize the life cycle cost.
One of the main tests Wärtsilä faces with these Ecuadorian projects is delivering the engines and pump units all the way from Finland, often to areas with extreme climatic and environmental challenges.
For example, with the recent Repsol-YPF crude-oil-burning power plant delivery, Wärtsilä faced a tight nine-month schedule and delivery to the remote location of Block 16. Wärtsilä considered a range of different transportation options, including shipping from Manaus through the Amazon River. This navigation was impossible with the secondary rivers at their lowest ebb at the time. It was then decided to ship the 36 MW power plant (comprising six 100 t Wärtsilä 32 18-cylinder crude oil engine-generating sets) from Finland to the Esmeraldas Port on the Pacific Ocean via the Panama Canal. The engines were then transported by land from sea level over the snow-capped Andes Mountains and down again to the Amazon jungle.
Occidental Eden Yuturi
The Occidental Eden Yuturi site in Ecuador proved to be a delivery challenge for Wärtsilä as well, but is now operating smoothly and effectively. In particular, the challenges of this project included a very remote location at the big Napo River, and no road access. Similarly to Dygoil and the OCP pipeline, the Eden-Yuturi project in the Amazon Region, Orellana Province, between El Edén and Yuturi towns has proven to be an efficient form of energy production. The 25 MW power plant is owned and operated by Occidental Petroleum Inc. and located on Block 15 in the remote Ecuador Oriente jungle.
Wärtsilä was contracted to deliver the plant for the oil field development site in eastern Ecuador in 2001, and it has now been operating since December 2002.
The Wärtsilä power plant will supply power to the drilling pumps, the central process facility and the oil boosting pipeline pumps via a medium voltage grid to the oil wells.
Long term solution
The power plant runs on crude oil and consists of four Wärtsilä 32LN engines, each producing 6.3 MW. With only minor changes to the engines and their fuel systems, the Wärtsilä engines perform as a conventional HFO plant. Universal Ensco completed the total site engineering and contract management.
The engines were delivered to the site in January 2002 and the plant has now been handed over to the customer. The long-term benefits of this installation include cheap fuels, and therefore cheap energy.
The engine technology required for these plants is not only a cost-saving option for oil and gas exploration companies located far from traditional power supplies, but also beneficial to the environment, because they convert what would normally be termed ‘waste’ fuels into energy at virtually no cost.